live moss in my enclosure?

I recently bought a package of live moss off of the internet because I thought it might spruce up my leo's enclosure. I put it in there and looked real close at it and I noticed the tiniest white bug living in it. It was microscopic, but it still scared me. So I immediately took it out and I am seeking any advice anyone has on growing live moss in an aquarium and if anyone can tell me if This tiny little bug could be a problem.